Cable modems include embedded software the occasionally must be updated, sometimes even remotely. However, early cable modems, such as those compliant with DOCSIS 1.0, provided no mechanism to authenticate the code file during Unit Update.
In contrast, subsequent versions of cable modems, such as those compliant with DOCSIS 1.1, provide for a mechanism to authenticate the code file during Unit Update. This process is known as the DOCSIS BPI+ code authentication process or commonly as Secure Software Download. While this process guarantees authentication during a download, this process does not provide authentication of an image when the image reboots in the device. Consequently, if an image gets modified by a hacker, and placed into the modem directly, currently there is no way to detect such an occurrence.
The present invention is therefore directed to the problem of developing a method and apparatus for authenticating an image of software in an electronic device, such as a cable modem.